Emulsifiers for Metal Working Fluids

ABSTRACT

Disclosed is the use of an alkoxylated fatty alcohol of formula (I), RO—(CH 2 —CHR′—O) n —(CH 2 CH 2 —O) m —H, wherein R stands for a saturated and/or unsaturated alkyl moiety containing 12 to 22 carbon atoms, R′ is methyl, ethyl or propyl, m represents a number of 1 to 12, preferably 4 to 10, and n represents a number of 1 to 10, preferably 2 to 8, as an emulsifier in metalworking fluids which also contain at least water and one oil component, non-miscible with water, and, optionally, further ingredients, and where the fatty alcohol which forms the R moiety has a iodine value of 15 to 75 g I 2 /100 g.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is the US National Stage application under 35 U.S.C. §371 of International application number PCT/EP2009/006228, filed on Aug. 27, 2009, which claims the benefit of priority of European application number 08015630, filed on Sep. 5, 2008, the disclosures of both of which are hereby incorporated by reference herein in their entireties.

FIELD OF THE INVENTION

The present invention pertains to emulsifiers, useful in metalworking fluids, as well as to metalworking fluids, containing those emulsifiers.

BACKGROUND OF THE INVENTION

Metalworking fluids, either based on petrochemical or natural oils, are well known in the art and utilized throughout the industry for a variety of processes including rolling, stamping, drawing, pickling, cutting and extruding. Aqueous formulations of various oils are widely used as the rolling oil in the cold rolling of steel to provide lubrication and to cool the rolls. In addition to providing effective lubrication and effective cooling of the workpiece/working elements, there are other criteria which must be met by metalworking fluids. Rolling oils, for example, must be capable of providing a continuous coating on the surface of the metal. Furthermore, this coating or film must have a minimum thickness and must be substantive enough to the metal so that it will be maintained at the high pressures which occur in the roll bite. Above and beyond these lubrication considerations it is particularly advantageous if the rolling oil provides some measure of corrosion protection to the rolled strip and burns off cleanly during the annealing operation. Residual rolling oil must volatilize cleanly and should not leave any carbonaceous deposits or surface discoloration. In view of variations in the metals being worked and the different operating conditions and application methods employed, numerous metalworking fluids have been developed in an attempt to obtain the optimum balance of properties. Most of these variations have involved the use of different fats and oils or replacement of a portion of the fat or oil with a petroleum product, e.g. mineral oil, or a synthetic lubricant, e.g. a synthetic hydrocarbon or ester.

Emulsifier systems have also been widely varied and additives have been employed to enhance the characteristics of these oils. Unfortunately, emulsions are quite unstable fluids. For example, they often show tendency to coalescence resulting in an increased mean particle size, changed particle size distribution and finally in oil and/or water separation. This instability is even more pronounced when operating under varying and severe process conditions. In this respect variables like make-up water quality/composition, temperature, pH, tramp oil and metal fines in the emulsion are considered important and crucial. In view of the above it is emphasized that the values of these variables can vary over wide ranges, well-known to those skilled in the art. For example, water hardness values of between 0° dH (demineralized water) and 40° dH for make-up water are observed. Also known is that after preparation of the emulsion the ionic strength and/or water hardness may change/increase significantly during the operation due to evaporation of water or incoming metal fines and ions, resulting in a reduction or loss of relevant properties like emulsion stability, film forming properties and dispersing capacity. Such instabilities of emulsions are highly undesirable. Users of metalworking emulsions strongly prefer stable emulsions having properties/performance which do not change over time. Therefore, in the research and development area, producers of these emulsions strive for maximization of the emulsion stability, especially under practical, varying operating conditions.

Unexpectedly, it has now been found that the stability problems of metalworking fluids, being oil-in-water emulsions, or even multiple emulsions, can be solved by using one or more alkoxylated fatty alcohols as emulsifiers. Surprisingly, this type of emulsion not only shows high emulsion stability under varying and severe processing conditions, but also provides good foam behavior, and shows good lubricating properties. Also the above-mentioned type of emulsifier shows high responsiveness to concentration changes. By varying the content of the emulsifier, the formulator can influence directly the size of the oil droplets in the emulsion, as desired.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph displaying foam height versus time for emulsifiers of formula (I), versus a commercial standard.

FIG. 2 is a graph displaying foam height versus time for inventive metalworking formulations including the emulsifiers of formula (I), versus a commercial standard.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A first embodiment of the present invention is directed to the use of an alkoxylated fatty alcohol characterized by the general formula (I)

RO—(CH₂—CHR′—O)_(n)(CH₂CH₂—O)_(m)—H  (I)

wherein R stands for a saturated and/or unsaturated alkyl moiety, containing 12 to 22 C-Atoms, R′ is a methyl-, ethyl-, or propyl-group, m represents an number of 1 to 12, and preferably 4 to 10, n represents a number of 1 to 10, and preferably 2 to 8, as an emulsifier in metalworking fluids, containing at least water and one oil component, non-miscible with water, and optionally further ingredients. The R moiety in formula (I) shows an iodine value of between 15 and 75 g I₂/100 g.

The compounds according to formula (I) are generally known. It is preferred to have an unsaturated alkyl moiety in the fatty alcohol part; mono-, di-, tri- and poly-unsaturated alkyl groups are all suitable. The alkyl moiety “R” can be branched or linear. Preferred fatty alcohols, used to prepare the compounds according to formula (I) are selected from mono-unsaturated fatty alcohols having 12 to 22, preferably 14 to 20 carbon atoms. Linear alcohols are preferred over the branched ones.

Preferred unsaturated fatty alcohols in this context are 10-undecen-1-ol, (Z)-9-octadecen-1-ol (common name, oleyl alcohol), (E)-9-octadecen-1-ol (common name, elaidyl alcohol), (Z,Z)-9,12-octadecadien-1-ol (common name, linoleyl alcohol), (Z,Z,Z)-9,12,15-octadecatrien-1-ol (common name, linolenyl alcohol), (Z)-13-docosen-1-ol (common name, erucyl alcohol), and (E)-13-docosen-1-ol (common name, brassidyl alcohol). Most preferred is oleyl alcohol.

Preferred saturated fatty alcohols in this context are 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-heneicosanol and 1-behenylalcohol. In addition, saturated, branched alcohols, such as Guerbet-type alcohols are also suitable. Most preferred is cetyl alcohol (hexadecane-1-ol).

As far as the alcohol-derived group “R” in formula (I) is concerned, the iodine value is also important. Preferred ranges for the iodine value (measured, for example, according to DGF-Method, C-V 17a) are from 15 to 75, more preferably from 20 to 75, still more preferably from 20 to 55, and most preferably from 25 to 50 g I₂/100 g. This value refers to the fatty alcohol stock, or mixture, used to prepare the alkoxylates according to formula (I).

The components according to formula (I) are mixed alkoxylates, i.e. containing at least ethylene oxide moieties together with propylene oxide, butylene oxide or pentylene oxide, whereby the most preferred alkoxides are ethylene oxide and propylene oxide. The indices m and n are numbers and may be integers or fractional numbers, as the alkoxides are statistically distributed during preparation. However, the teaching of the present invention encompasses alkoxides with a narrow range of alkoxides as well.

The alkoxylated components according to formula (I) are prepared by standard methods known by the skilled person. The fatty alcohol is reacted with the alkoxides in the presence of alkaline catalysts at a temperature of about 120 to 220° C. and a pressure of about 100 to 500 kPa, to form the alkoxylated end-product.

It is especially preferred to use such components according to formula (I) wherein the amount of ethylene oxide is equal to or higher than the amount of the other alkoxide, i.e. m≧n. Preferred values for m are in the range from 4 to 10, and in particular 4 to 8; preferred values for n are in the range from 1 to 8, in particular from 1 to 5, and most preferably from 1 to 3. However, also preferred are compounds where n stands for 4 to 6. In addition, a preferred selection encompasses compounds according to formula (I) wherein m is 4 to 10, and n is 1 to 8, or 1 to 5, or 1 to 3.

In the compounds according to formula (I) the sequence of addition of ethylene oxide and the other alkoxide is not critical, and can be randomized (mixed sequence of different alkoxides) or block-wise.

However, it is a preferred embodiment that the compound according to formula (I) contains two blocks: preferably, the first one, adjacent to the alkyl moiety, contains the alkoxide, preferably propylene oxide, and the last block contains the ethylene oxide. Such compounds can be described with the general formula RO—(CH₂CR′—O)_(n)(CH₂—CH₂—O)_(m)—H, or more simply as RO—(PO)_(n)-(EO)_(m)—H.

However, the above described general formula (I) is not to be understood as being limited to any specific sequence of the alkoxides moieties. Thus, this formula covers also block-wise alkoxylated products like RO-(EO)_(m)—(PO)_(n)—H, and also randomly distributed homologues thereof.

Generally, those compounds according to formula (I) are preferred in which R′ stands for a methyl group, i.e. those compounds contain both ethylene oxide and propylene oxide together.

A further preferred embodiment of the present invention pertains to the use of a blend of components according to formula (I), in which R represents in the one compound a saturated moiety, and in the other compound an unsaturated moiety. The blends of saturated and unsaturated compounds according to formula (I) may vary across a broad range of weight ratio, for example the saturated compound is present in amounts from 1 to 99% by weight, and the unsaturated compound is present in amounts from 99 to 1% by weight. But, in cases when those combinations of saturated and unsaturated compounds are used, the amount of saturated compounds of formula (I) could be greater than the amount of unsaturated compounds according to formula (I). For example, the amount of the unsaturated compound is in the range from 51 to 99% by weight, and the amount of the saturated compound is from 1 to 49% by weight in a preferred embodiment of the present invention.

However, a most preferred blend according to the invention contains oleyl-(C18′) and cetyl (C14)-based compounds according to formula (I) together. These compounds may be present together in weight ratios from 99:1 to 1:99, and particularly in the ratio from 4:1 to 1:4, and most particularly in the weight ratio from 9:1 to 3:1. It is particularly useful to have an excess of the oleyl-based compound.

The use of alkoxylated fatty alcohols as emulsifiers for metalworking fluids is not new per se. GB 1 462 357 discloses, for the purpose of emulsifying, a combination of fatty alcohol alkoxylates together with diesters of dicarboxylic acids. However, GB 1 462 357 disclosed in the examples only ethoxylated fatty alcohols, having saturated alkyl moieties. In contrast the present invention selects alkoxylated fatty alcohols having at least two different kinds of alkoxylates in the molecule. It is further preferred to avoid the use of such diesters of dicarboxylic esters in using the claimed process of the present invention. From WO 2008/089857 A1 cooling lubricants for the wet machining of aluminum alloyed magnesium are known. In particular the use of water miscible emulsions, containing particular fatty alcohols, propoxylated and ethoxylated, in combination with selected corrosion inhibitors for this purpose are disclosed. On page 15 in “Tabelle 1” a specific fatty alcohol, based on a blend of C12-C14 alcohols, and being ethoxylated and propoxylated (3 EO+6 PO) is disclosed. Those compounds are not preferred in the meaning of the present teaching, and could be excluded from protection therefore. The same is true in regard to the particular blend of the ethoxylated oleyl alcohol, and the propoxylated oleyl/cetyl alcohol as given in this “Tabelle 1” on page 15 of WO 2008/089857 A1. From WO 2008/071582 A2 it is known, that propoxylated and ethoxylated tallow fatty alcohols with an iodine value below 1 g I₂/100 g, can be used as emulsifiers.

Concerning the oil component of the emulsions according to the invention it is stated that such a component can be selected from the group consisting of mineral oils, synthetic lubricants, natural triglycerides and blends of all mentioned base fluids. Mineral oils are obtained by oil drilling and then fractionated and purified. Other known oil components useful in metalworking fluids according to the present invention are esters, poly-alpha-olefins, polyglycols, and the like, all having a hydrophobic character and for that reason suitable for the preparation of the metalworking fluids according to the invention. In particular, esters may be selected from the group consisting of (a) natural esters like vegetable and animal fats and oils, being triglycerides of glycerol and fatty acids, and (b) synthetic esters of polyalcohols (polyols) and fatty acids of natural and synthetic origin. Examples of synthetic esters include, without limitation, esters of fatty acids and polyols, the latter including pentaerythritol, trimethylolpropane, neopentylglycol, and the like.

As the metalworking fluids according to the invention are preferably oil-in-water emulsions, in their final use the oil content is generally at most 20 weight-%, preferably less than 15 weight-% and most preferably less than 10 weight-%. However, for concentrated emulsions the oil content may even be up to 60 weight-%, for instance 50 weight-%.

Generally, those compounds according to formula (I) are preferred in which R′ stands for a methyl group, i.e. those compounds contain both ethylene oxide and propylene oxide together.

The emulsifier according to the invention is present in the final metalworking fluids in amounts of preferably 0.1 to 25 weight-%, more preferably in amounts from 1 to 15 weight-%, and most preferably in amounts from 1.5 to 10 weight-%.

The metalworking fluids according to the invention are preferably oil-in water (o/w)-emulsions and more particularly (o/w)-macro-emulsions having a mean particle size above 0.1 μm. Preferred ranges are from 0.1 to 100 μm, and most preferred from 0.1 to 45 μm.

Further, the metalworking fluids may comprise typical additives, such as sulfur additives, for instance, a sulfurized oil or fat, anti-wear agents and/or extreme pressure additives, as well as corrosion inhibitors, defoamers, biocides and yellow metal deactivators, and/or solubilizers. Thus, a preferred embodiment of the invention encompasses the use of an alkoxylated fatty alcohol characterized by the general formula (I) as an emulsifier in metalworking fluids, containing at least water and one oil component, non-miscible with water, and optionally, further ingredients selected from the group of sulfur additives, anti-wear agents, extreme pressure additives, corrosion inhibitors, defoamers, biocides, yellow metal deactivators and solubilizers.

A corrosion inhibitor is a highly preferred additive in the metalworking fluids according to the invention. Corrosion inhibitors are typically selected from, but not limited to, a system containing a blend of fatty acids, fatty acid amides, and/or fatty acid alkylamides, and/or fatty acid alkanolamides.

A typical yellow metal deactivator can be selected from the families of the azoles. Illustrative azole-type corrosion inhibitors are benzotriazole, tolutriazole, the sodium salt of mercapto-benzotriazole, naphthotriazole, methylene bis-benzotriazole, dodecyltriazole and butylbenzotriazole, preferably tolutriazole.

Besides the emulsifiers according to the invention, additional emulsifiers of different structure are preferred components in the metalworking fluids. Typically, one emulsifier is hydrophobic in nature, where the other emulsifier is more hydrophilic. Co-emulsifiers are, for example, selected from ethoxylated fatty alcohols, alkoxylated fatty acids or phenol-type emulsifiers. Up to five different emulsifiers can be present in a metalworking fluid.

The emulsifiers according to the present invention will be preferably combined or blended together with other additives, preferably corrosion inhibitors and co-emulsifiers, together with the oil and water to form a concentrate, which itself is then used to form a ready-made metalworking fluid.

Thus, a further embodiment of the present invention pertains to an emulsion concentrate, containing at least one emulsifier according to formula (I), one co-emulsifier, a corrosion inhibitor, an oil component and, optionally, other ingredients, characterized in that the amount of emulsifier according to formula (I) is at least 2% by weight, more preferably at least 5% by weight, and at maximum 30% by weight, preferably 25% by weight. Emulsion concentrates are commonly the commercial forms of water-miscible metalworking fluids. These concentrates contain typically an emulsifier system, comprising at least two different emulsifiers, a corrosion inhibitor system, and a base oil (mineral oils, ester oils, polyglycols and the like), and optionally, additional ingredients such as defoamers, biocides, solubilizers and extreme pressure and/or anti wear additives (so-called EP/AW additives). The amount of emulsifiers in such concentrates ranges from 5 to 30% by weight, the base oil is present preferably in amounts from 50 to 75% by weight, corrosion inhibitors are present in amounts from 5 to 15% by weight, biocides are used in amounts from 0.01 to 1% by weight, solubilizers are preferably present in amounts from 1 to 5% by weight, and the EP/AW-additives are used in amounts from 2 to 10% by weight, with the proviso that the sum of all ingredients is 100% by weight. Water can be present also in smaller amounts, such as 5 to 25% by weight, but it is only an optional ingredient.

The emulsions according to the invention can be obtained in two different ways. Directly, the emulsions (in their final use) are prepared by emulsification in water of an emulsifiable oil containing the alkoxylated fatty alcohols according to the invention. Indirectly, the emulsions can be prepared in 2 steps by first making a concentrated emulsion (or using a concentrate, as described above), and second by simply diluting this concentrated emulsion with water. The concentrated emulsion is an oil-in-water emulsion of about 60 weight-% oil in water stabilized with the alkoxylated fatty alcohol emulsifiers. The final emulsion can be prepared by simply diluting the concentrated emulsion with water.

A further aspect of the invention is directed to the use of the metalworking fluids in metalworking processes. Typical metalworking processes involve elastic deformation, plastic deformation and cold working of metals, with or without metal removal. In some of these operations the metal piece is deformed only; like in rolling and drawing of steel and aluminum, while in others metal is removed rather than deformed, like in cutting, grinding, broaching, machining and drilling of metals. The metallic material from which the metalworking apparatus and articles to be fabricated are made, include steel, cast iron, and ferrous alloys, as well as aluminum alloys and other non-ferrous alloys, including such components as titanium, magnesium, copper, tin and brass.

A last embodiment of the current application pertains to a metalworking fluid, containing at least a water-phase, an oil-phase which is not miscible with water, an emulsifier, and additional compounds, selected from the group of emulsifiers, co-emulsifiers, corrosion inhibitors, yellow metal deactivators, defoamers, biocides, EP- and/or AW-additives, and solubilizers, characterized that the fluid contains in amounts of 0.1 to 20.0% by weight as emulsifier of at least one compound according to formula (I).

Examples

Two new emulsifiers were synthesized using standard alkoxylation methods and run through different application tests in comparison to a commercial nonionic emulsifier containing 5 parts of ethylene oxide.

1. Synthesis of Emulsifier A

333 g of oleyl/cetyl-alcohol were mixed with 1.4 g KOH solution and dried under vacuum. Then 221 g of propylene oxide (PO) was added first at 170-180° C. and a pressure of at maximum 5 bars. After the propoxylation reaction had taken place, 146 g of ethylene oxide (EO) were added under the same conditions. After successful take-up of the oxides, the reaction was continued for another 60 minutes. Then the reaction mixture was cooled, neutralized, and filtered through TONSIL® brand bleaching earth, and CELATOM® brand diatomaceous earth, to yield a pale yellow, liquid product. The following physical data were measured to characterize the material:

Density at 15° C. 0.9520 g/cm³ Viscosity at 40° C. 24.8 mm²/s Viscosity at 100° C. 6.0 mm²/s VI 172 Cloud point 4° C. Pourpoint 3° C. Turbidity point in butyl 62° C. diglycol HLB value 10.5

All measurements where carried out according to DIN methods.

2. Synthesis of Emulsifier B

244 g of oleyl/cetyl-alcohol were mixed with 1.4 g KOH solution and dried under vacuum. Then 214 g of propylene oxide was added first at 170-180° C. and a pressure of at maximum 5 bars. After the propoxylation reaction had taken place, 243 g of ethylene oxide was added under the same conditions. After successful take-up of the oxides the reaction was continued for another 60 minutes. Then the reaction mixture was cooled down, neutralized, and filtered through TONSIL® brand bleaching earth, and CELATOM® brand diatomaceous earth, to yield a pale yellow, liquid product. The same data as with Emulsifier A were measured to characterize the material:

Density at 15° C. 0.978 g/cm³ Viscosity at 40° C. 40.6 mm²/s Viscosity at 100° C. 8.4 mm²/s VI 188 Cloud point 8° C. Pourpoint 0° C. Turbidity point in butyl 68° C. diglycol HLB value 14.0

3. Comparison of Foaming Behavior

Emulsifier A, emulsifier B and a commercial nonionic emulsifier with 5 EO were compared in terms of foaming. To evaluate the 3 components a test was used as described below, using the SITA FOAM TESTER® R-2000:

-   -   Prepare a 1% solution in water     -   Place 300 ml of the solution in a beaker     -   Run test under stifling using the following parameters:

Sample volume: 300 ml Temperature: 20° C. tolerance: +/−0.5° C. Stirrer velocity: 1100 min⁻¹ Time of stirring: 10 sec. Cycles: 3 Interval of measurement: 10 sec. Time of foam decomposition: 20 min/0 ml foam height Cleaning: shortened

-   -   The foam height is recorded for each interval and the decay over         20 minutes.     -   Average values of foam height versus time are displayed in a         diagram.

The build-up and decrease of the foam is showed in FIG. 1 for Emulsifier A and B in comparison with the commercial 5 EO product. It can be clearly seen that both new emulsifiers generate much less foam than the commercial 5 EO emulsifier, which has a higher foaming tendency despite the higher HLB values of the new emulsifiers A and B.

4. Lubrication Behaviour

The three previously tested emulsifiers were used in a basic frame formulation containing base fluid, corrosion protection package and emulsifier package. The following formulations were used to evaluate Emulsifier A and B:

Content (w/w) Formulation A Formulation B Formulation C 50.00% Ester Ester Ester 5.80% Monoethanolamine Monoethanolamine Monoethanolamine 2.20% Triethanolamine Triethanolamine Triethanolamine 14.00% Tall oil fatty acid Tall oil fatty acid Tall oil fatty acid 3.80% Fatty Acid C8 Fatty Acid C8 Fatty Acid C8 6.00% Alkanolamide Alkanolamide Alkanolamide 10.60% Hydrophobic Hydrophobic Hydrophobic emulsifier emulsifier emulsifier 2.70% Butyldiglycol Butyldiglycol Butyldiglycol 4.90% Emulsifier A Emulsifier B Commercial 5 EO product

The three frame formulations were tested for lubricating performance using the Reichert Rig. The recorded wear scars are listed below.

Formulation A Formulation B Formulation C Wear Scar 14.7 15.0 15.5

Both new emulsifiers show matching performance to other commercial emulsifier.

5. Comparison of Foaming Behavior of Formulations

All three formulations prepared for the lubrication test were run through the same foam test as the pure emulsifiers.

The build-up and decrease of the foam is showed in FIG. 2 for Formulation A and B in comparison with Formulation C. The results and conclusions of the pure emulsifiers could be clearly mirrored in the respective frame formulations.

6. Emulsion Behaviour in Different Base Fluids

To show the versatility towards different base fluids the three emulsifiers were blended in specific percentage in 4 different fluids: two esters of different chemical structure (Trimethylolpropane-trioleate, TMP-trioleate; 2-ethylhexyloleate, 2-EH-oleate) and 2 petrochemical fluids (Naphthenic oil; Paraffinic oil).

These concentrates were then diluted 5% in water for a particle size measurement. Average, median and maximum values of the oil droplet distribution were recorded. All three values should ideally be very equal. But due to the logarithmic scale of the x axis higher deviations can be accepted when bigger droplets are present. The average value equals the particle size, which represents the arithmetic middle particle size when recognizing the logarithmic scale. The median value represents the particle size, till which 50% of all oil droplets are measured. The maximum value represents the particle size, of which the high percentage is present in the emulsion.

The results are given in tables 1 and 2, below, for both of the new emulsifiers in the 4 different base fluids.

TABLE 1 Concentration Appearance Appearance Average Value Median Value Maximum Value Base Oil Emulsifier Emulsifier Concentrate Emulsion [μm] [μm] [μm] TMP-trioleate A 10% Clear OK 13.69 6.21 4.87 20% Clear OK 6.281 5.831 8.537 25% Clear OK 15.29 10.16 23.82 2-EH-oleate A 10% Little Haze separated 16.82 11.72 34.59 20% Little Haze OK 12.7 7.806 7.084 25% Little Haze OK 10.02 6.756 6.45 Naphthenic Oil A 10% Cloudy OK 12.28 10.91 18 20% Cloudy OK 18.87 18.29 21.7 25% Cloudy OK 14.14 7.69 4.05 Paraffinic Oil A 10% Little Haze OK 11.69 7.973 13.61 20% Little Haze OK 3.035 2.706 3.06 25% Little Haze OK 0.46 0.486 0.688

TABLE 2 Concentration Appearance Appearance Average Value Median Value Maximum Value Base Oil Emulsifier Emulsifier Concentrate Emulsion [μm] [μm] [μm] TMP-trioleate B 20% Little Haze Creaming 24.99 13.95 34.59 2-EH-oleate B 10% Little Haze separated 20.11 14.73 41.68 20% Little Haze OK 13.76 9.806 34.59 25% Little Haze OK 4.235 1.384 0.117 Naphthenic Oil B 10% Little Haze OK 12.33 7.733 12.4 20% Clear OK 8.968 6.991 9.026 25% Clear OK 0.131 0.088 0.088 Paraffinic Oil B 10% Haze Creaming 17.02 11.59 26.15 20% Little Haze OK 6.452 2.329 2.313 25% Clear OK 0.123 0.122 0.117

It can be seen, that Emulsifier A is highly suitable for all kinds of base fluids, while Emulsifier B is more effective in terms of mono-esters in higher concentrations and in general for petrochemical base oils.

As comparative example the same measurements as for Emulsifiers A and B where carried out for Example C. As can be seen in Table 3 the droplet size is only weakly influenced by the concentration of emulsifier C, and the properties of the emulsions are less advantageous than the emulsions prepared in accordance with the invention. In particular, the concentration of the emulsifier C does not trigger the droplet size in the same manner as the inventive emulsifiers A and B.

TABLE 3 Concentration Appearance Appearance Average Value Median Value Maximum Value Base Oil Emulsifier Emulsifier Concentrate Emulsion [μm] [μm] [μm] TMP-trioleate C  5% Clear OK 4.91 3.005 2.539 10% Little Haze Creaming 3.379 2.263 2.107 30% Cloudy Separate 4.806 2.842 2.539 

1-13. (canceled)
 14. A method of metalworking comprising the step of treating metal with a metalworking fluid, comprising: (a) one or more oil components which are non-miscible with water, (b) water, (c) one or more emulsifiers selected from the group consisting of alkoxylated fatty alcohols of formula (I) RO—(CH₂—CHR′—O)_(n)(CH₂CH₂—O)_(m)—H  (I) wherein R stands for a saturated and/or unsaturated alkyl group containing 12 to 22 carbon atoms, and is derived from a fatty alcohol; R′ is methyl, ethyl or propyl; m represents a number of 1 to 12; and n represents a number of 1 to 10, and (d) optionally, further ingredients, wherein said fatty alcohol which forms the R moiety has an iodine value of 15 to 75 g I₂/100 g.
 15. The method of claim 14, wherein m is 4 to
 10. 16. The method of claim 14, wherein n is 2 to
 8. 17. The method of claim 14, wherein R comprises oleyl, and R′ comprises methyl.
 18. The method of claim 14, wherein component (c) comprises a mixture of at least two different compounds of formula (I), and wherein one compound contains an unsaturated R group, and the other compound contains a saturated R group.
 19. The method of claim 18, wherein one R group comprises oleyl, and the other R group comprises cetyl.
 20. The method of claim 1, wherein said one or more emulsifiers of formula (I) are present in the metalworking fluid in an amount of 0.1 to 25% by weight.
 21. The method of claim 20, wherein said emulsifiers are present in 1 to 20% by weight.
 22. The method of claim 21, wherein said emulsifiers are present in 1.5 to 10% by weight.
 23. The method of claim 1, wherein said iodine value is in the range of 20 to 55 g I₂/100 g.
 24. The method of claim 1, wherein said metalworking fluid is an emulsion.
 25. The method of claim 24, wherein said emulsion is an oil-in-water emulsion.
 26. The method of claim 1, wherein R′ is methyl, and the ethylene oxide and propylene oxide moieties of formula (I) are distributed randomly.
 27. The method of claim 1, wherein R′ is methyl, and the oxides are distributed block-wise, with the propylene oxide block adjacent to the fatty alcohol group, followed by the ethylene oxide block.
 28. The method of claim 1, wherein n is a number in the range of 1 to
 5. 29. The method of claim 28, wherein n is a number in the range of 1 to
 3. 30. The method of claim 1, excluding the co-use of diesters of dicarboxylic acids.
 31. An emulsion concentrate, comprising: (a) one or more oil components, (b) water, (c1) 2-30% by weight, based on the concentrate, of one or more emulsifiers of formula (I) RO—(CH₂—CHR′—O)_(n)(CH₂CH₂—O)_(m)—H  (I) wherein R stands for a saturated and/or unsaturated alkyl group containing 12 to 22 carbon atoms, and is derived from a fatty alcohol; R′ is methyl, ethyl or propyl; m represents a number of 1 to 12; and n represents a number of 1 to 10, (c2) at least one additional emulsifier, (d1) a corrosion inhibitor system, and (d2) optionally, other ingredients.
 32. The method of claim 31, wherein the amount of said one or more emulsifiers of formula (I) is 3-25% by weight, based on the concentrate.
 33. A metalworking fluid, comprising: (a) an oil phase which is not miscible with water, (b) a water phase, (c) 0.1-20% by weight, based on the fluid, of one or more emulsifiers of formula (I) RO—(CH₂—CHR′—O)_(n)(CH₂CH₂—O)_(m)—H  (I) wherein R stands for a saturated and/or unsaturated alkyl group containing 12 to 22 carbon atoms, and is derived from a fatty alcohol; R′ is methyl, ethyl or propyl; m represents a number of 1 to 12; and n represents a number of 1 to 10, and (d) one or more additional compounds selected from the group consisting of corrosion inhibitors, yellow metal deactivators, defoamers, and biocides. 